I don't think your theory of overstabilization plays out in the elr crowd. They are running much faster than "needed" twist in order to pass the transonic range more cleanly.
From our shooting and testing we have seen no downside to running bullets in the range of 2.0 sg, and higher, calculated at sea level out to long range hunting ranges.
It was once thought that a bullet fired at marginal stability would be better for long range for the reason that you describe. So the nose will break over as the bullet trajectory does. I have hunted with bullets that are very accurate with marginal stability and have seen less than stellar results on game. Marginal stability will greatly increase the odds of bullet failure on game. Bullets tumbling on impact or not opening up due to yaw. The lower the rpm's the more quickly the bullet loses stability after impact causing the bullet to not track straight though an animal. This becomes ultimately important with quartering shots.
To the OP. As some others have said, your needs will most likely be met with any twist rate offered in factory rifles shooting factory ammo. I would recommend that you stay away from the 11" twist that are in some of the 30cal offerings. You should not rule out the faster twist that is available in the Browning. There is not a downside. Some have said that you will lose vel. Not enough to accurately measure or be noticeable from one rifle to the next. It may cost you ~25fps going from a 10" twist to an 8" twist. This is not enough to be noticed. You could get an 8" twist barrel that is faster than a 10" twist barrel just because of variation from one barrel to the next.
There is one effect of a faster twist compared to the slower twist than has not been mentioned, that actually happens. The faster twist will impart more spin drift than the slower twist with the same bullet. This is easily compensated for, so not really an issue.
My .02
